[libc++] Implement P2445R1 (`std::forward_like`)

Co-authored-by: A. Jiang <de34@live.cn>

Reviewed By: philnik, huixie90, #libc

Differential Revision: https://reviews.llvm.org/D132327

NOKEYCHECK=True
GitOrigin-RevId: 3a49cffe3add478c2381ed79c56e1e105dd0fa16
diff --git a/docs/FeatureTestMacroTable.rst b/docs/FeatureTestMacroTable.rst
index 0ffd44d..8860578 100644
--- a/docs/FeatureTestMacroTable.rst
+++ b/docs/FeatureTestMacroTable.rst
@@ -314,6 +314,8 @@
     ------------------------------------------------- -----------------
     ``__cpp_lib_constexpr_typeinfo``                  *unimplemented*
     ------------------------------------------------- -----------------
+    ``__cpp_lib_forward_like``                        ``202207L``
+    ------------------------------------------------- -----------------
     ``__cpp_lib_invoke_r``                            *unimplemented*
     ------------------------------------------------- -----------------
     ``__cpp_lib_is_scoped_enum``                      ``202011L``